Sample tests

I commented earlier on #2 and threw together a quick sample test using Approvals.

Note 1: it would be better to use something like Jasmine or Mocha (I like Mocha) to set each test instead of a single node.js script - but it's the simplest thing at the moment.

Note 2: I was struggling with line-endings. I put a simple `.gitattributes` in and re-set the files. I tried to make the commits meaningful. While looking at the diff of all won't help (due to line-endings changes). other commits should give context of changes.

Note 3: Would be good to put other sample data/posts into the test and verify the output is correct (saving the `*.approved.txt` files.

Hope this helps.